In such a loom, hooks disposed in rows are alternately raised by bars or blades commonly called “knives” or “griffes”, these knives or griffes themselves most often being supported by one of the two griffe frames. Each frame must be animated by a vertical oscillatory movement in phase opposition with the other frame.
To that end, it is known from FR-A-2 669 650 to use an input shaft animated by a continuous movement of rotation and on which are mounted four eccentrics each associated with a connecting rod for controlling a rocking lever, the rocking levers being mounted, in groups of two, on shafts provided on each side of the frames. This kinematics is relatively complex and expensive, while it is delicate to adjust, particularly due to the high number of articulations resulting from the use of four eccentrics and four control rods. In addition, auxiliary frames or plates must be added on the frame of the loom in order to support, on the one hand, the input shaft and, on the other hand, the shafts on which the rocking levers are mounted.
It is a more particular object of the invention to overcome these drawbacks by proposing a novel, simplified shed forming device whose reliability is improved and which is easier to assemble and to adjust than the known devices.